TRANSIENT STABILITY ANALYSIS OF MULTIMACHINE POWER SYSTEM USING CRITICAL MACHINE ENERGY FUNCTIONS AND FIRST SWING STABILITY ANALYSIS OF SVC

Abstract

Transient stability analysis is an indispensible part of utility system planning. The industry standard for transient stability performance varies from region to region, but it requires the ability of the system to withstand severe disturbances such as faults or switching of lines. Under this event, system linearization is not possible and the Differential Algebraic Equation model of the power system need to be solved. Even though several direct stability methods have been developed since the inception and identification of stability problem in multimachine system, numerical method of solving the stability problem is still carried out exploiting the features of digital computation. The result of this method is still being used as the benchmark for determining the precision of direct methods of stability analysis. Keeping in hand with the convention, Numerical method of solving stability problem has been carried out in this project. Stability analysis of multi-machine power system using energy functions of individual machine and group of machines has been the main subject matter of this research study. The simulations carried out reaffirm the concept of critical machines in stability analysis. These are the machines which contribute to instability, and their transient energy separate them from the rest of the system. Critical clearing time, an important parameter in design of circuit breakers and various other protection equipments has been determined using energy functions of individual machines, and critical group of machines. The values obtained using critical machine energy function are found to be more accurate. Power systems worldwide are undergoing transformation into complex entities with the introduction of various fast controllers such as FACTS devices. Stability analysis incorporating FACTS devices is the need of the hour. Some preliminary effort in this regard has been carried out in this project. Initially the analysis have been carried out on SMIB system and later on expanded to multi-machine power system by utilising the advantages of MATLAB and DIGSILENT POWER FACTORY software.